The Brazilian Energy Plan (PNE 2030) that guides the Government in formulating its strategy for expanding energy supply by 2030 highlights the need for the Brazilian electrical system have more than 4,000 MW from nuclear sources by 2025. Therefore, the Government presented a proposal to build four more nuclear power plants with capacity of 1,000 MW each, at first, two in the Northeast and two in Southeast. The selection and site assessment are key parts of the installation process of a nuclear plant and may significantly affect the cost, public acceptance and safety of the facility during its entire life cycle. The result of this initial stage, it can even seriously affect program success. Wrong decisions in the process of site selection may also require a financial commitment to higher planned in a later phase of the project, besides causing extensive and expensive downtime. Select the location where these units will be built is not a trivial process, because involves the consideration of multiple criteria and judgments in addition to obtaining, organizing and managing a diverse range of data, both qualitative and quantitative, to assist in decision making and ensure that the site selected is the most appropriate in relation to safety and technical, economic and environmental feasibility. This paper presents an overview of the site selection process and its stages, the criteria involved in each step, the tools to support decision making that can be used and the difficulties in applying a formal process of decision making. Also discussed are ways to make the process more transparent and democratic, increasing public involvement as a way to improve acceptance and reduce opposition from various sectors of society, trying to minimize the expense and time involved in the implementation of undertakings of this kind.